Node module generating a lot of subfolders

I'm running my build on jenkins but when I run npm install --color=false --loglevel warn it generate a lot of subfolders, and I can't even delete them on windows (I have to rename them before that).

It has started to happen today, we didin't manually update anything

Node problem

My packages.json file

{
  "name": "contratanet-portal",
  "version": "0.1.0",
  "description": "Builder do contratanet portal",
  "private": true,
  "devDependencies": {
    "grunt": "~0.4.5",
    "grunt-shell": "~0.7.0",
    "grunt-msbuild": "~0.1.12",
    "grunt-nuget": "~0.1.3",
    "underscore": "~1.6.0",
    "karma": "^0.12.23",
    "karma-jasmine": "^0.1.5",
    "requirejs": "^2.1.15",
    "karma-chrome-launcher": "^0.1.4",
    "karma-firefox-launcher": "^0.1.3",
    "lodash": "^2.4.1",
    "karma-opera-launcher": "^0.1.0",
    "karma-safari-launcher": "^0.1.1",
    "karma-ie-launcher": "^0.1.5",
    "karma-junit-reporter": "^0.2.2",
    "karma-phantomjs-launcher": "^0.1.4",
    "grunt-karma": "^0.9.0"
  }
}